Edward j



(N0 Modl.)

E. J. MALLETT, Jr.

BOILER OR OTHER FURNACE.

Patented May 23, 1882.

HHHIHIIHI WITNESSES NrrEn STATES EDWARD J. MALLE'IT, JR, OF NEW YORK, N. Y.

BOILER OR OTHER FURNACE.

SPECIFICATION forming part of Letters Patent No. 258,452, dated May 23, 1882.

Application filed November 28, 1881.

To all mzom it may concern:

Be it known that I, EDWARD J. MALLETT, J r., of the city, county, and State of New York, have invented certain new and useful Improvements in Boiler and other Furnaces, of which the following is a specification.

My improvements in furnaces are directed mainly to means whereby the admission of air to the furnace for the purpose of supporting the fire may be regulated so as to obtain more perfect combustion than is usually the case.

In my improved furnace air for insuring the combustion offuelis admitted not only through the tubular grate-bars, which introduceit into the furnace at a point beyond the bridge-wall, but also through the ash-pit, whence it passes up between the grate-bars to the fire in the usual way. With the air-inlet openings of the grate-bars and ash-pit I combine registers or gates by which the proportionate volume of air passing through each can be controlled and varied at pleasure; and I preferably combine with these two sets of registers alever-handle connected to and adapted to operate simultaneously both sets in'such manner that in proportion as the one is closed the other will open.

The nature of my invention will be understood by reference to the accompanying drawings, representing a boiler-furnace embodying the several features hereinbefore specified.

Figure 1 is a front elevation of the furnace. Fig. 2 is a longitudinal vertical section of so much of the fire-box as needed to illustrate my improvements. Fig. 3 is an enlarged and perspective view of the front portion of one ofthe tubular grate-bars. Fig. 4 is a like view of a key, which can be used for the purpose of rotating and reciprocating the several grate-bars.

A is the tire-box, B the ash-pit, and O the bridge-wall, of the furnace. These parts may be of ordinary or suitable construction.

With a view to readily keep clean the grate bars, I have in the drawings shown them arranged so that they may both reciprocate lengthwise and rotate on their axes, as has heretofore in some instances been done.

The grate-bars a, which are shown as tubular and open from end to end, are supported at the front in bearings in the front wall of the furnace, and at the rear in tubular bearings formed preferably in a metallic bearing-block, I), held in the bridge-wall. The tubular bear- (No model.)

ings are internally flanged at the rear, as at 0, so as to prevent the bars from being pushed too far inward. The grate-bars are supported in these hearings, so that they maybe capable not only of rotary movement on their axes, but also of reciprocatory movement in the direction of their length; and to permit of the latter movement without rendering the bars liable to drop the rear bearings, 11, are elongated, as shown in Fig. 2. The bars can be readily rotated and reciprocated by suitable means-as, for instance, by a key such as illustrated in Fig. 4, provided with an inner end slotted, as shown at 01, so that it may be fitted to and engaged with a cross-pin, e, which is secured in the open front end of each tubular bar, as seen in Fig. 3. The stem or handle of the key is jointed at the point f, so that the outer portion of the handle may be bent at right angles to the other part, in order to obtain the leverage required in order to rotate the grate-bar. Air is admitted to the furnace at two points through the grate-bars a,whence it is discharged at a point beyond the bridgewall, so as to mingle with the gaseous pro ducts of combustion and through openings 9 in the ash-pit, whence it passes up between the grate-bars to the fire in the usual way. I find this key a very convenient adjunct to use in the foregoing connection. It is manifest, of course, that if desired the bayonet-slots maybe formed in the tubular grate-bars, in which event the pin would be in the key, arranged so that its ends would project sufficiently to enter and engage the slots when the key is fitted. to the bar. It is essential to regulate the pro portionate volumes of air admitted at these two points so as to insure perfect combustion and to this end I provide the inlet ends of the grate-bars with a sliding register or gate, h, and the inlet-openings g of the ash-pit with a like register, a. These two registers or sets of registers can be opened or closed more or less, so as to determine with nicety the quantity of air admitted at each point. I prefer to connect them both by means of jointed connecting-rodsj to opposite arms of a lever-handle, 7c, pivoted or fulcrumed at'l to the furnacefront, the arrangement being such that in proportion as the one set, h, closes the other, 1:, opens, and vice versa. This feature is particularly advantageous in connection with a furnace in which the draft through both ashpit openings and grate-bars is induced and maintained by the drawing or sucking action of an active mechanical appliance, such as a suction-fan, (as described and claimed by me in another application for Letters Patent of even date herewith,) which draws through the furnace a stated and definite volume of air; but it is also applicable to furnaces in which draft is obtained in other ways.

The register-openings in the slide-register h are of such size that when brought opposite the front ends of the grate-bars they will permit the bars as they reciprocate to pass in and out through them. Other provision, however, may be made for this purpose. For instance, the register can be made removable, or it may be otherwise arranged, so that, when desired, it can drop away or be removed from the inlet ends of the bars.

I have described and shown the tubular grate-bars as conducting air to a point behind the bridge-wall. They may, however, if desired, be arranged to discharge the air into the bridge-wall made hollow or with passages for this purpose, whence the air can be led and discharged into the furnace at the required point.

Having described my improvements, what I claim, and desire to secure by Letters Patent, 1s

1. In a furnace, the combination, substalr tially as hercinbefore set forth, of tubular grate-bars open from end to end and conducting air from the outside into or beyond the bridge-wall, air-inlet passages in the ash-pit which admit air beneath the grate-bars, and registers applied to and controlling both the open inlet ends of the grate-bars and the airinlet passages of the ash-pit, substantially as hereinbefore set forth.

2. The combination, with the tubular gratebars and the air-inlet passages of the ash-pit, of registers applied to the outer ends of the bars and the air-inlets of the ash-pit respectively, and the lever-handle connected to and adapted to operate simultaneously both sets of registers, so that in proportion as the one is closed the other will open, substantially as hereinbefore set forth.

3. The combination of the tubular grate-bar, adapted both to slide lengthwise and rotate, and the removable key, provided, the one with bayonet-slots and the other with pin to engage said slots, substantially as and for the purposes here'inbefore set forth.

In testimony whereof I have hereunto set my hand this th day of November, 1881.

EDWARD J. MALLETT, JR.

Vitnesses:

IIERMANN ALBERT, E. J. MALLETT. 

